"There is a region in Japan where there are lots of people over 100 years old - they have a saying called 'ikigai', which is Japanese for 'your reason and purpose to get up in life'," says Dr Dickinson.

"If your ikigai is very strong, your purpose could be giving family support like looking after grandchildren, then you have a purpose in life; whereas those who retire and then don't do very much, [it] tends to drop off."

It's just one of the theories as to why people live longer lives – she describes a recent study that puts why women live longer than men down to three reasons.

"Heart disease – it's to do with diet," says Dr Dickinson. "It also comes down to smoking, and men tend to be apple-shaped instead of pear-shaped, meaning that they carry their fat [in their stomach]."

Carrying fat around your stomach sits around other organs and creates a higher risk of heart disease.